Phase equilibria of the Sn-Sb binary system

Sn-Sb alloys are important high-temperature solders. However, inconsistencies are found in the available phase diagrams, and some phase boundaries in the Sn-Sb system have not been determined. Sn-Sb alloys were prepared, equilibrated at 160 degrees C to 300 degrees C, and the equilibrium phases and their compositions were determined. The beta-SnSb phase has a very wide compositional homogeneity range, and its composition varies from Sn-47.0at.%Sb to Sn-62.8at.%Sb. There is no order-disorder transformation of the beta-SnSb phase. There are three peritectic reactions in the Sn-Sb system, L + Sb = beta-SnSb, L + beta-SnSb = Sn(3)Sb(2), and L + Sn(3)Sb(2) = Sn, and their temperatures are 424 degrees C, 323 degrees C, and 243 degrees C, respectively. Thermodynamic models of the Sn-Sb binary system were developed using the CALPHAD approach based on the experimental results of this study and the data in the literature. The calculated phase diagram and thermodynamic properties are in good agreement with the experimental determinations.